Scanning confocal single molecule spectroscopy instrument -UH Description: custom designed and built, experimental equipment is composed of a choice of CW or pulsed laser excitation. The CW source is from a 6 W 532 nm diode laser (Coherent Verdi). This laser also pumps the pulsed laser, which is a tunable Ti:saph femtosecond laser with fundamental mode-locked output from 750-890 nm for two-photon excitation and with frequency doubled output for UV/visable excitation (KM Labs). A three axis piezo scanning stage (Physik Instrumente) with a house-machined temperature-controlled sample holder is used for x-y-z sample scanning and positioning with 1 nm precision. Confocal excitation/detection is performed using a high numerical aperture achromatic objective (Zeiss). Avalanche photodiodes (Perkin Elmer) are used for single-photon fluorescence detection. The scanning and photon counting are both controlled by a fast analog controller (RHK) for optimal scanning/imaging speeds. Location: SR1, room 7C PI: Christy Landes